Field of the Invention
The present invention relates to a device and method for performing hybrid imaging of organs and tumors. More particularly, an endorectal probe is provided for imaging of a prostate gland wherein the probe (device) has combined positron emission tomography and ultrasound imaging modalities.
Description of the Background Art
There are >200,000 new cases and nearly 30,000 deaths each year from prostate cancer (PCa) Prostate-specific antigen (PSA) testing has allowed early detection of impalpable PCa. Early detection has lowered the incidence of advanced disease with extracapsular extension and the subsequent early treatment appears to improve survival rate. After anomalous PSA results, the patient undergoes biopsy, and if the biopsy is positive, the patient undergoes surgery. The main objective of surgery is to remove the cancer at lowest functional cost, i.e. preserving continence and sexual function. The stage of the cancer decides the limits of the resection, and the larger the tumor the wider the excision needed, with radical prostatectomy as the limit of standard treatment. An accurate localization of the tumor and assessment of its size has two important advantages: it can direct the biopsy and can assist with the surgery. Biopsy results may be negative despite the presence of cancer due to sampling error. Prostate cancer is the only human cancer that does not have a standard method to image the primary tumor. The “blind” biopsy typically performed today under ultrasound (US) guidance results in high false negative diagnosis with many missed cancers. Accurate localization of the tumor, within the prostate and pelvic region, will better enable a tumor-free margin. Such accurate assessment today is not available with conventional imaging techniques [ultrasound (US), computed tomography (CT), magnetic resonance imaging and PET]. Standard PET scanners have spatial resolution inadequate to meet the clinical needs of prostate imaging—particularly when using specific, targeted imaging agents.
The diagnosis of prostate cancer is commonly based on a combination of digital rectal examination (DRE), serum prostate specific antigen (PSA) value, and transrectal ultrasound (TRUS) guided prostate biopsy findings. Conventional blind “biopsy” procedures under Tissue Differentiating Ultrasound are able to visualize only the structure and the margins of an organ, and thus do not provide differentiation between a cancerous tissue and healthy tissue.
Prostate cancer is the only human cancer that does not have a standard reliable method of imaging of the primary tumor. Functionally blind biopsy typically performed today under transrectal ultrasound guidance results in high false negative diagnoses with many missed cancers. Accurate localization of the tumor, within the prostate and pelvic region, will allow definition of a tumor-free margin. Such accurate assessment is generally not available in the present state of the art, with the conventional imaging techniques available to urologists.
The main problem is that prostate cancer is difficult to visualize in its early stage using current imaging technology. Conventional imaging modalities, such as ultrasound, CT (computed tomography) scan, and MRI (magnetic resonance imaging), can be used for the anatomic evaluation of prostate cancer. However, visible anatomic changes are not always present in early stages of the disease, making the use of current imaging modalities difficult in early detection of prostate cancer sites. The key problem with conventional guiding systems during prostate biopsy is that they are based on symmetrical anatomical sampling of the prostate, and not on the location of the cancer. The main challenge continues to be the inability to visualize the cancer in its early stages using current imaging technology.
U.S. Pat. No. 7,894,876 “Combined MR-optical coil for prostate, cervix, and rectum cancer imaging diagnostics” discloses a combined MR and optical system that may be used to guide a biopsy.
U.S. Pat. No. 7,711,409 “Opposed view and dual head detector apparatus for diagnosis and biopsy with image processing methods” discloses opposed gamma cameras for guiding a biopsy needle, but discloses no ultrasound imaging components.
U.S. Pat. No. 7,653,427 “Method and instrument for minimally invasive sentinel lymph node location and biopsy” discloses a radiation detector coupled with an ultrasound probe, for locating the position of a tagged tissue, and placement of a biopsy device.
U.S. Pat. No. 6,951,542 “Method and apparatus for ultrasound imaging of a biopsy needle or the like during an ultrasound imaging examination” discloses method including imaging and injection of contrast agents for placement of a biopsy device.
U.S. Pat. No. 6,546,279 “Computer controlled guidance of a biopsy needle” discloses a system for guiding a biopsy needle using one or more of computed tomography imaging, magnetic resonance, fluoroscopic imaging, or 3-D ultrasound imaging.
U.S. Pat. No. 6,512,943 “Combined ultrasound-radionuclide device for percutaneous ultrasound-guided biopsy and method of use” discloses a system and apparatus for performing tissue biopsy. An ultrasound imager and a “radionuclide detectors” are used, external to a patient, to locate “nuclear medicine tracer uptake” in the patient and generate superimposed images of an area of interest.
U.S. Pat. No. 5,776,062 “Enhanced breast imaging/biopsy system employing targeted ultrasound” discloses a system using X-ray imaging and ultrasound, external to a patient, to provide 3-D imaging of an area of interest for use with a biopsy procedure.
U.S. Pat. No. 5,170,055 “Radiation detecting biopsy probe” discloses a handheld biopsy probe that is guided by means of a scintillation crystal, but uses no ultrasound imaging. The device is used externally on a patient, as the primary application is for the detection of tumors in lymph nodes.
U.S. Pat. No. 5,014,708 “Radioactive ray detecting therapeutic apparatus” discloses a “radioactive ray guided” therapeutic device, where in one embodiment, the delivered therapy comprises destroying target cells by ultrasound, and removal of the cells by aspiration.
U.S. Pat. No. 4,995,396 “Radioactive ray detecting endoscope” discloses an endoscope having both an ultrasonic imaging device and a radioactive ray (e.g., beta radiation) detecting device in the tip of the endoscope, but does not disclose use of a biopsy device.
U.S. Pat. No. 4,781,198 “Biopsy tracer needle” discloses a method and device for obtaining a tissue sample, comprising a biopsy tracer needle (i.e., containing a radiation source) guided to a target tissue by means of an external scintillation device. No use of ultrasound is disclosed.
U.S. Published Application No. 2009/0270760 “Biopsy devices” discloses a biopsy device utilizing an isotope-tagged needle mounted to a cradle support mechanism, where PET scanning is used to position the needle in a target tissue by manipulation of the cradle. No use of ultrasound is disclosed.
U.S. Published Application Serial No. 2007/0282221 “Ultrasound assist and X-ray assist biopsy devices” discloses a biopsy table, where a biopsy needle may be directed to a targeted tissue area by using an X-ray guided procedure for locating micro-calcifications, and using an ultrasound guided procedure for locating lesion masses.
U.S. Published Application Serial No. US 2010/0198063 A1 “Multi-Modality Of Phantoms And Methods For Co-Registration Of Dual PET-Transrectal Ultrasound Prostate Imging” discloses use of a PET scanner and a transrectal ultrasound (TRUS) probe. The TRUS probe is inserted into the rectum of a patient for acquiring a TRUS image data of the prostate stepwise and then moving the patient bed to position the point sources near the external PET-center and acquiring the image, and then superimposing the PET image with the TRUS image for gaining a resulting image showing an anatomical and functional detail.
What is needed is a probe, and more specifically a prostate endorectal probe, and an imaging system, and method of evaluating a target organ of a patient, which overcomes the shortcomings of the present state of the art.